Influence of Atomic Lines on Radiative Heating of Entering Space Vehicles

2011 ◽  
Author(s):  
Sergey Surzhikov ◽  
Joseph Shang
Keyword(s):  
Radiative Heating ◽  
Space Vehicles ◽  
Atomic Lines

Radiative-Collisional Models in Non-Equilibrium Aerothermodynamics of Entry Probes

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Sergey T. Surzhikov
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Low Temperature ◽  
Chemical Kinetic ◽  
Gas Mixtures ◽  
Hypersonic Flows ◽  
Radiative Heating ◽  
Space Vehicles ◽  
Physical Chemical ◽  
Kinetics Of

To design space vehicles aimed for returning payloads from a geostationary orbit, the Moon and other large or small planets of Solar system, a knowledge of the total (convective and radiative) heating from an environment is required. It is well known that the radiative heat load on a space vehicle moving through the atmosphere increases as the speed and the size increase, therefore, in many of these missions the large part of the trajectory will pass at high altitude, where the low atmospheric density can lead to significant thermal, chemical and physical nonequilibrium effects. Physical models and computational codes used to predict the aerothermodynamics must account for not only high temperature equilibrium thermodynamics (as a rule, within the framework of the local thermodynamic equilibrium (LTE) approach), but also for nonequilibrium one. Therefore, an accurate prediction of radiative heating as well as convective one under both equilibrium and nonequilibrium conditions becomes important to designers and space mission planners. To develop a prediction computational fluid dynamics (CFD) tool for reentry flows, where dissociation, ionization and radiation are important, some major areas are addressed. The most significant of them are following: (1) physical-chemical kinetics of high temperature dissociated and ionized gases, (2) transport properties of the gas mixtures, (3) spectral radiation properties of high temperature gases and low-temperature plasmas, (4) numerical simulation algorithms for prediction of nonequilibrium gas mixtures dynamics and radiation heat transfer in volumes of various geometry, and (5) models of physical and chemical processes accompanied by interaction of gas flows and radiation with thermoprotection systems (TPS) of space vehicles (including their thermochemical destruction, ablation, sublimation, etc.). In literatures (See Refs. (Park, C, 1990, Nonequilibrium Hypersonic Aerothermodynamics, Willey-Interscience Publication, J. Wiley & Sons, New York; Park, C., 1993, “Review of Chemical Kinetic Problems of Future NASA Missions. I: Earth Entries,” J. Thermophys. Heat Transfer, 7(3), pp. 385–398; Park, et al., 1994, “Review of Chemical-Kinetic Problems of Future NASA Missions, II: Mars Entries,” J. Thermophys. Heat Transfer, 8(1), pp. 9–23; Sarma, G., 2000, “Physico-Chemical Modelling in Hypersonic Flow Simulation,” Prog. Aerosp. Sci., 36, pp. 281–349; Huo, and Thuemmel, 1995, Electron-Air Molecule Collisions in Hypersonic Flows. Molecular Physics and Hypersonic Flows, Capitelli M., ed., Kluwer Academic Publishers, pp. 115–138.)) one can find reviews of governing equations used in the aerophysics, boundary conditions and the associated inputs using the physical-chemical models and their partially successful applications. This article presents the states of the art of models of electronic kinetics in the nonequilibrium low-temperature plasma of complex chemical compositions (air and carbon dioxide mixtures) widely met in various aerospace applications. Special attention is given to electronic kinetics of atoms and diatomic molecules within the framework of the radiative-collisional models.

Rate of Sublimation of Ice by Radiative Heating in Freeze-Etching

1980 ◽  
Vol 38 ◽  
pp. 618-619
Author(s):  
Yeshayahu Talmon
Keyword(s):  
Heat Flux ◽  
Freeze Fracture ◽  
Constant Heat Flux ◽  
Radiative Heating ◽  
Constant Heat ◽  
Entire Sample ◽  
Simplified Method ◽  
Freeze Etching ◽  
Sublimation Rates ◽  
Fractured Surface

To bring out details in the fractured surface of a frozen sample in the freeze fracture/freeze-etch technique,the sample or part of it is warmed to enhance water sublimation.One way to do this is to raise the temperature of the entire sample to about -100°C to -90°C. In this case sublimation rates can be calculated by using plots such as Fig.1 (Talmon and Thomas),or by simplified formulae such as that given by Menold and Liittge. To achieve higher rates of sublimation without heating the entire sample a radiative heater can be used (Echlin et al.). In the present paper a simplified method for the calculation of the rates of sublimation under a constant heat flux F [W/m2] at the surface of the sample from a heater placed directly above the sample is described.

STARK SHIFT AND BROADENING OF ATOMIC LINES AS OBSERVED ON OPTOGALVANIC SPECTRA OF NOBLE GASES

1983 ◽  
Vol 44 (C7) ◽  
pp. C7-497-C7-504 ◽  
Author(s):  
T. Nakajima ◽  
N. Uchitomi ◽  
Y. Adachi ◽  
S. Maeda ◽  
C. Hirose
Keyword(s):  
Noble Gases ◽  
Stark Shift ◽  
Atomic Lines

Strategy comparison for space vehicles' active existence terms estimation during protracted acceptance testing

2001 ◽  
Vol 7 (1s) ◽  
pp. 15-18
Author(s):  
O.G. Baibuz ◽  
◽  
S.V. Zemlyanaya ◽  
F.A. Pristavka ◽  
◽  
...  
Keyword(s):  
Acceptance Testing ◽  
Space Vehicles
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